JP6426716B2 - Production of molybdenum-99 using electron beam - Google Patents

Description

  The present disclosure relates to manufacturing processes, systems, and apparatus for manufacturing molybdenum-99. More particularly, the present disclosure relates to manufacturing molybdenum-99 from a molybdenum-100 target using a high power electron linear accelerator.

Technetium- ^99m (hereinafter ^99m Tc) is one of the most widely used radioactive tracers in nuclear medicine diagnostics. ^99m Tc is used to detect various forms of cancer, for cardiac stress testing, to calculate bone density, to image selected organs, or for other diagnostic tests It is used on a daily basis. ^99m Tc emits 140 keV gamma radiation that is easily detectable and has a half-life of only about 6 hours, limiting the patient's exposure to radioactivity.
Thanks to this extremely short half-life, medical centers equipped with nuclear medicine equipment use a ^99m Tc generator to obtain ^99m Tc from the decay of ^99m Tc's parent isotope molybdenum-99 ( ⁹⁹ Mo). ⁹⁹ Mo has a relatively long half-life of 66 hours, enabling worldwide transport from a nuclear facility to a medical center, and mass production of ⁹⁹ Mo is derived from fission of highly enriched ²³⁵ uranium . The problem with this ⁹⁹ Mo nuclear production is that its global supply begins with five reactors built in the 1960s, and the end of life of these reactors is near.

Nearly two-thirds of the world supply of ⁹⁹ Mo currently consists of two reactors: (i) the National Research Universal Reactor at the Chalk River Institute in Ontario, Canada, and (ii) the Petten Reactor in the Netherlands It is made from. In the past few years, a serious deficiency of ⁹⁹ Mo has occurred as a result of planned or unplanned outages in both of these major production reactors.
As a result, a serious shortage occurred in medical facilities within a few weeks of reactor shutdown, causing a significant decrease in the provision of medical diagnostic tests, and in addition, there was significant manufacturing demand for the remaining reactors. Currently, both facilities are in operation, but there is significant global uncertainty regarding the reliable long-term supply of ⁹⁹ Mo.

Exemplary embodiments of the present disclosure, by high energy electron irradiation of the linear accelerator, apparatus for producing molybdenum -99 ⁽⁹⁹ Mo) molybdenum -100 ⁽¹⁰⁰ Mo), system, and the manufacturing process. Some exemplary embodiments of the present disclosure relate to a system for performing the manufacturing process of the present disclosure. Some exemplary embodiments of the present disclosure relate to an apparatus comprising the system of the present disclosure.

The present disclosure will be described in conjunction with the following reference drawings.
1 is a perspective view of an exemplary system of the present disclosure, with a protective shield in place. FIG. FIG. 2 is a perspective view of the exemplary system of FIG. 1 with the protective shield removed. FIG. 3 is a side view of the exemplary system of FIG. 2 with the protective shield removed from the linear accelerator portion of the system. FIG. 4 is a top view of the exemplary system shown in FIG. 3. FIG. 4 is an end view of FIG. 3 showing one end of the linear accelerator section. 6A is a perspective view showing the target assembly portion of the exemplary system of FIG. 2 with the protective shield portion partially removed. On the other hand, FIG. 6 (B) is a perspective view showing the target assembly part with the protective shield removed. FIG. 2 is a side view of a target drive assembly (perpendicular to the electron beam generated by a linear accelerator). FIG. 2 is a front view of a target drive assembly showing an entrance for a bremsstrahlung photon beam generated from an electron beam of a linear accelerator. FIG. 9 is a cross-sectional side view of the target drive assembly shown in FIG. 8. FIG. 9 is a top view of the target drive assembly shown in FIG. 8 at the junction of the cooling tower and the beamline housing. It shows an energy converter and the Turn-target holder mounted on the beam line, a top sectional view of a target drive assembly shown in FIG. FIG. 2 is a schematic diagram for converting a high-power electron beam into a bremsstrahlung photon shower for illuminating a large amount of ¹⁰⁰ Mo target. A expansion larger cross-sectional side view of FIG. 9 shows a energy-saving transducer and te target holder mounted on the beam line. Is an enlarged top cross-sectional view of FIG. 11 shows an error Nerugi transducer and te target holder mounted on the beam line. FIG. 15A is a perspective view of an exemplary target holder, and FIG. 15B is a cross-sectional side view of the target holder. 16A is a perspective view of the top surface of an exemplary refrigerant tube portion, FIG. 16B is a perspective view of the bottom surface of the refrigerant tube portion, and FIG. 16C is a refrigerant tube. It is a cross-sectional side view of a part. 17 (A) and 17 (B) show another embodiment of the refrigerant pipe portion disposed in the target assembly portion of FIG. 18A and 18B show the refrigerant pipe part of FIG. 17 fixed at a predetermined position in the target assembly part. FIG. 2 is a perspective view of an exemplary remote controlled molybdenum processing apparatus mounted on a protective shield sheath of the target assembly station portion of the exemplary system shown in FIG. 1. FIG. 20 is a perspective view of an exemplary frame support for the exemplary remote control molybdenum processing apparatus shown in FIG. 19. FIG. 21 is a perspective view of an exemplary shuttle tray cooperating with the exemplary frame support shown in FIG. 20. FIG. 22 is a perspective view of an exemplary shield cask that can be mounted on the exemplary shuttle tray shown in FIG. 21; FIG. 20 is another perspective view of the exemplary remote control molybdenum processing apparatus shown in FIG. 19. FIG. 24A is a perspective view of an exemplary grapple portion of the exemplary remote control molybdenum processing apparatus shown in FIGS. 19 and 23 shown engaged with a crane hook. (B) is a cross-sectional side view of an exemplary grapples unit shown engaged with exemplary molybdenum target holder. FIG. 24 is a perspective view of an exemplary tilt tower removably engaged with the exemplary remote control molybdenum processing apparatus shown in FIGS. 19 and 23, the exemplary tilt tower receiving a refrigerant tube assembly. Configured to hold. FIG. 26 is a horizontal cross-sectional view of the exemplary tilt tower shown in FIG. 25.

Exemplary embodiments of the present disclosure relate to systems, apparatus, and manufacturing processes for manufacturing ⁹⁹ Mo from a ¹⁰⁰ Mo target using high energy radiation of an electron beam generated by a linear particle accelerator.

Linear particle accelerators (also referred to as “linacs”) are particle accelerators that significantly increase the velocity of elementary charged particles by applying a series of oscillating potentials to the charged particles along a linear beam line. The generation of a linac electron beam generally requires the following components:
A source (typically a cathode device) for generating electrons (i) for initial injection of electrons into a hollow tube vacuum chamber (iii) whose overall length depends on the desired energy for the electron beam A high voltage source (ii), a plurality of electrically insulated cylindrical electrodes (iv) arranged along the entire length of the hollow tube, and a high frequency energy source for applying a voltage to each of the cylindrical electrodes ( That is, one energy source per electrode (v), a quadrupole magnet (vi) surrounding a hollow tube vacuum chamber for focusing the electron beam, a suitable target (vii), and electron beam irradiation. Cooling system (viii) for cooling the target during.
Linacs are routinely used for a variety of applications (eg, x-ray generation) and to generate high energy electron beams to provide radiation therapy to cancer patients.

In addition, linacs are commonly used as injectors for high energy accelerators such as synchrotrons, and also achieve the highest kinetic energy that can be made into light particles for use in elementary particle physics by bremsstrahlung. Can be used directly for.
Bremsstrahlung is electromagnetic radiation that is usually generated by the deceleration of charged particles when electrons around the nucleus are deflected by another charged particle. The movement of electrons loses kinetic energy because energy is stored, but the kinetic energy is converted into photons.
The bremsstrahlung has a continuous spectrum that becomes more intense as the energy of the accelerated electrons increases and its peak intensity shifts towards higher frequencies.

However, those skilled in the art will recognize that using an electron linear accelerator to generate high energy photons via bremsstrahlung and then to generate radioisotopes via photonuclear reaction. It may be considered an inefficient manufacturing process for manufacturing the body. This is because the electromagnetic interaction between a nucleus and an electron is usually much smaller than a strong interaction with a proton such as an incident particle.
However, we, ¹⁰⁰ Mo is the around 15 MeV photon energy leads to a significant increase in the reaction cross section between ¹⁰⁰ Mo and ⁹⁹ Mo, broad neutron reaction of light "Giant dipole resonance" (GDR ). Also, the emission length of high energy photons in the 10-30 MeV range of ¹⁰⁰ Mo is about 10 mm, which is considerably longer than the high energy protons in the same range. Therefore, effective target thickness, as compared to proton reaction, towards the photoneutron reaction is very large.

The reduction in the number of reaction channels associated with the electron beam produced at the linac limits the production of undesirable isotopes. In comparison, generating ⁹⁹ Tc directly from ¹⁰⁰ Mo using a proton beam often results in the generation of other Tc isotopes from other stable Mo isotopes present in the enriched ¹⁰⁰ Mo target. Will bring.
In medical applications, severe constraints are imposed on the amount of other radioisotopes in which ⁹⁹ Tc may be present, and the production of ⁹⁹ Tc from linac-generated electrons and ¹⁰⁰ Mo is not possible with other Tc. This is preferred because the risk of producing isotopes is very low.
In addition, photoneutron reactions with other Mo isotopes present in the ¹⁰⁰ Mo target usually result in stable Mo.

Accordingly, one embodiment of the present disclosure, for the production of ⁹⁹ Mo from a plurality of ¹⁰⁰ Mo target by light nuclear reaction ¹⁰⁰ Mo target, an electronic beam apparatus of an exemplary high power linac.
This device generally has 5kW power, about 10kW power, about 15kW power, about 20kW power, about 25kW power, about 30kW power, about 35kW power, about 45kW power, about 45kW power, about 60kW power, An electron linear accelerator (i) capable of generating an electron beam of approximately 75 kW, approximately 100 kW, and a high energy bremsstrahlung with a high flux of at least 20 MeV from the electron beam generated by the linear accelerator Bremsstrahlung photon with flux about 25MeV, bremsstrahlung photon with flux about 30MeV, bremsstrahlung photon with flux about 35MeV, bremsstrahlung photon with flux about 40MeV, bremsstrahlung with flux about 45MeV A water-cooled converter (ii) for generating photons, and a target holder containing a plurality of ¹⁰⁰ Mo target disks are attached to the interior, and the target holder is accurately positioned and aligned, and the water-cooled converter Of high energy bremsstrahlung photon radiation generated by In order to prevent leakage of radiation from the device by enclosing gamma rays and / or neutron rays in the target assembly portion and the water-cooled target assembly portion (iii) of the water-cooled transducer for blocking And a plurality of shield parts (iv) for covering the water-cooled target assembly part.

Depending on the components protected by the shield and the mounting location, the shield can include one or more of lead, steel, copper, and polyethylene.
The apparatus further comprises an integrated target transport assembly (v) with components for remotely loading and transporting a plurality of target holders. With this target transport assembly, each target holder is loaded together with a plurality of ¹⁰⁰ Mo target disks into the target drive.
Individual loaded target holders can be transported from the loading / conveying section to a target driving section provided in the water-cooled target assembly section by remote control.
The target holder is transported by the target drive to a position that blocks bremsstrahlung photon radiation.

The base of the target drive engages with a target alignment centering that accurately positions and aligns the loaded target holder so as to block bremsstrahlung photon radiation as much as possible.
An integrated target transport assembly also removes the irradiated target holder remotely from the target drive, transports it to a lead-protected hot cell, and ⁹⁹ associated with the irradiated ¹⁰⁰ Mo target disk. It is configured to separate and recover ^99m Tc that decays from Mo.
Alternatively, the irradiated ¹⁰⁰ Mo target disk may be transported into a lead-protected transport container for transport to a hot cell remote from the site.

Clearly, the maximum achievable ⁹⁹ Mo yield depends on the amount of energy that can be safely deposited in a ¹⁰⁰ Mo target disk and the probability of a giant dipole resonant photon interacting with the target nucleus. It is.
The amount of energy that can be safely deposited in this ¹⁰⁰ Mo target disk depends on the heat capacity of the target assembly.
¹⁰⁰ Mo if a large amount of heat from the target disk can be quickly transferred, ^{before 100} Mo target disk is melted, it would be possible to deposit more energy ¹⁰⁰ Mo target disk.
Water is a desirable refrigerant because it facilitates large heat dissipation and is economical.

Unfortunately, as the electron beam passes through the cooling water in the bremsstrahlung transducer section, the energy associated with the electron beam causes radiolysis of the water.
Radiolysis of water, among other things, hydrogen gas produces the risk of explosion, and further, to produce hydrogen peroxide with a corrosive to molybdenum, thereby, potentially from ¹⁰⁰ Mo target disk Greatly reduces the practically feasible ⁹⁹ Mo yield.
In addition, the energy associated with the bremsstrahlung photons passing through the cooling water in the water-cooled target assembly that houses the ¹⁰⁰ Mo target disk causes the generation of hydrogen peroxide from the water. Few.

Thus, in another embodiment of the present disclosure, the heat load from the water cooled energy converter and the water cooled target assembly section is dissipated separately to maximize the production of ⁹⁹ Mo from a ¹⁰⁰ Mo target disk. In order to enable this, separate cooling water systems are required for these two components.

It is within the scope of this disclosure to incorporate into the first cooling water system for the bremsstrahlung conversion section an apparatus, facility or device for combining hydrogen gas and oxygen to form water in the circulating water.
It is optional to use a gaseous refrigerant to cool the bremsstrahlung conversion part or to replenish cooling water to the bremsstrahlung conversion part.

The second cooling water system for the water-cooled target assembly section incorporates one or more buffers to improve the corrosive action in the circulation of hydrogen peroxide, sacrificial metals, and supplemental gaseous refrigerant to molybdenum. That is within the scope of this disclosure.
Examples of suitable buffering agents include lithium hydroxide and ammonium hydroxide. Examples of suitable sacrificial metals include copper, titanium, and stainless steel.

An exemplary high power linac electron beam device 10 for producing ⁹⁹ Mo from a plurality of ¹⁰⁰ Mo targets is shown in FIGS.
The apparatus 10 includes a 35 MeV, 40 kW electronic linac 20 manufactured by Mevex (Ottawa, Ontario, Canada), a collimator station 25 for focusing an electron beam generated by the linac 20, and a target irradiation chamber 42 (FIGS. 6 to 11). Reference), a cooling tower assembly 32, a coolant supply source 34, and a target assembly station 30 including a vacuum device 36 connected to a target irradiation chamber 42 by a vacuum tube 37.
The components 20, 25, 30 of the linac electron beam apparatus 10 are shielded with a protective shield sheath 15 for containing and confining gamma rays and / or neutron rays.

The 35 MeV, 40kW electronic linac 20 is a 3-cell 1.2m S-band on-axis coupled standing wave section, 3 modulators and a high duty factor klystron with a peak of 5MW, and Equipped with a 60-kV thermionic gun.
The linac 20 is attached to a support frame 22 provided with a plurality of rollers 23, and the linac 20 can be separated from the collimator station 25 for accessing and maintaining the components of the collimator station 25.
The collimator station 25 includes a water-cooled tapered copper pipe that communicates with the first cooling water system. This tapered copper tube has an electron beam generated by the linac 20 on a diameter of about 0.075 cm to 0.40 cm, about 0.10 cm to about 0.35 cm, about 0.15 cm to about 0.30 cm, about 0.20 cm to about 0.25 cm. It has a beryllium window for squeezing.

The target assembly station 30 includes a support plate 39 of a support member 38, and a target irradiation chamber having an inlet tube 40 for sealingly engaging the electron beam delivery tube 28 on the support member 38. 42 is attached (refer FIG. 6 (A) and FIG. 6 (B)).
The cooling tower 32 is engaged directly above the target irradiation chamber 42 so as to be sealed with the target irradiation chamber 42, and the target holder 80 is attached in the radiation process.
The vacuum tube 37 and the transducer station cooling assembly 34 are attached so as to be sealed on the side surface of the target irradiation chamber 42 (see FIGS. 6A and 6B).

The cooling tower 32 includes a refrigerant tube housing 44, and the refrigerant tube housing 44 is engaged with the refrigerant tube cap assembly 45 by a plurality of nuts 45 a at the distal end.
The refrigerant tube cap assembly 45, in this embodiment, includes a plurality of rods 48 for remote control engagement by a crane (not shown) to lift and separate the cooling tower 32 from the target irradiation chamber 42. (See FIGS. 7 to 9).
The refrigerant water supply pipe 100 (see FIGS. 16A to 16C) is housed in the refrigerant pipe housing 44 and is engaged with the refrigerant pipe cap assembly 45 so as to be sealed. 46 is in communication with the second cooling water system.

The cooling water supply pipe 100 (see FIGS. 16A to 16C) includes an upper hub assembly 101 at the proximal end, a refrigerant supply pipe 103, a plurality of guide fins 104 at the other proximal end, and The cooling tube holder 105 for detachably engaging the target holder 80 is provided.
The upper hub assembly 101 is provided with a hook 102 for remote control introduction by an overhead crane (not shown) in order to attach the cooling water supply pipe 100 to the refrigerant pipe housing 44 and to remove it from the refrigerant pipe housing 44. Yes.
The outer shield 106 is positioned around the refrigerant supply tube 103 to position the refrigerant supply tube 103 within the refrigerant tube housing 44 and to provide a shield for the bremsstrahlung photon shower entering the refrigerant tube housing 44. Is provided.

The outer surface of the outer shield 106 is provided with a plurality of channels so as to allow cooling water to flow. The refrigerant supply tube 103 is provided with an inner upper shield 107 and an inner lower shield 108 to provide a shield for the bremsstrahlung photon shower entering the refrigerant supply tube 103.
Cooling water is supplied from the second cooling water supply system via the water inlet pipe 46 to the proximal end of the refrigerant supply pipe 103 via the inlet port (not shown) of the upper hub assembly 101. Then, cooling water is supplied from the tip of the refrigerant supply pipe 103 and passes through the cooling pipe holder 105.
Thereafter, the cooling water circulates in a space between the outside of the refrigerant supply pipe 103 and the inside of the refrigerant pipe housing 44 so as to return to the upper hub assembly 101, and then the ports 109 provided in the upper hub assembly 101, It is discharged from the cooling water supply pipe 100 through 110.

The coolant supply pipe 103 is provided with a plurality of fins 104 whose outer diameters are generally cooling pipe holders 105, and these fins 104 are attached to the refrigerant pipe housing 44 by an overhead crane (not shown), It functions as a guide for remote control introduction of the cooling water supply pipe 100 to be removed from the refrigerant pipe housing 44.
The refrigerant tube housing 44 includes a refrigerant tube alignment assembly 47 to allow accurate alignment of the cooling water supply tube 100 within the refrigerant tube housing 44.
The coolant water that is supplied to the target irradiation chamber 42 by the cooling tower 32 and circulates is then returned to the second cooling water system.

The target irradiation chamber 42 has an inner chamber 55 in which a bremsstrahlung transducer station 70 adjacent to the electron beam inlet tube 40 is incorporated (see FIGS. 11, 13, and 14).
The bremsstrahlung transducer station 70 is accessible through a transducer station cooling assembly 34 that is sealingly engaged to the side of the target illumination chamber 42.
The converter station cooling assembly 34 includes a cooling water pipe 50 that receives the cooling water flow from the first cooling water system and circulates the cooling water to the bremsstrahlung converter station 70.
The cooling water pipe 50 is accommodated in the housing 35.

Further, it is the vacuum tube 37 interconnected with the vacuum device 36 that is integrally engaged with the side surface of the target irradiation chamber 42 and communicates with the inner chamber 55.
After the high power linac electron beam device 10 is assembled, the integrity of the beryllium window seal at the beryllium window and collimator station 25 and the silicon window (or alternatively between the inlet tube 40 and the bremsstrahlung transducer station 70). , The integrity of the diamond window) is evaluated by applying a vacuum to the chamber 55 by the vacuum device 36 via the vacuum tube 37.

The bremsstrahlung transducer station 70 includes a series of four thin tantalum plates 26 (see FIG. 12) arranged at a 90 ° angle with respect to the electron beam 21 (see FIG. 12) produced by the linac 20.
However, it should be noted that the number and / or thickness of the tantalum plates 26 can be varied to optimize and maximize the photon generation generated by the electron beam.
It is optional to use plates containing alternative high density metals exemplified by tungsten and tungsten alloys containing copper or silver.
The tantalum plate 26 converts incident electrons into a bremsstrahlung photon shower 27 when illuminated with a high energy electron beam (see FIG. 12). The bremsstrahlung photon shower 27 is directly supplied to a target holder 80 that houses a plurality of ¹⁰⁰ Mo target disks 85 (see FIGS. 13 and 14).

Note that the transducer may comprise four or more tantalum plates, or less than four tantalum plates (eg, one tantalum plate, two tantalum plates, three tantalum plates, 5 One tantalum plate or more.
Alternatively, the plate 26 can include tungsten, copper, cobalt, iron, nickel, palladium, rhodium, silver, zinc, and / or alloys thereof.
The structure and configuration of the converter station 70 dissipates the large thermal load imposed by the high energy electron beam to minimize transmission to the photon shower and reduce the thermal load transmitted to the ¹⁰⁰ Mo target during irradiation. It has been designed.
The target holder 80 for accommodating the tantalum plate 26 and the plurality of ¹⁰⁰ Mo target disks 85 includes the cooling water (i) passing through the tantalum plate 26 by the first cooling water system and the ¹⁰⁰ Mo target by the second cooling water system. The cooling water (ii) passing through the disk 85 is cooled during the irradiation process by a constant circulation.

Another embodiment of the present disclosure relates to a target holder for receiving and receiving a plurality of ¹⁰⁰ Mo target disks 85.
An exemplary target holder 80 that houses 18 ¹⁰⁰ Mo target disks 85 is shown in FIGS. 15 (A) and 15 (B).
A plurality of grooves 82 for engaging with the cooling tube holder 105 at the distal end of the cooling water supply pipe 103 are provided at both ends of the target holder 80.
The target holder suitable for irradiating a ¹⁰⁰ Mo target of the exemplary high power linac electron beam apparatus 10 in the present disclosure is about 4 to 30, about 8 to 25, about 12 to 20, It should be noted that any number of ¹⁰⁰ Mo target disks in the range from about 16 to 18 can be accommodated.

A suitable ¹⁰⁰ Mo target disk can be manufactured by pressing commercial ¹⁰⁰ Mo powder or pellets onto the disk and then sintering the formed disk.
Alternatively, the precipitated ¹⁰⁰ Mo powder and / or granules recovered from a pre-irradiated ¹⁰⁰ Mo target can be sintered after being pressed into a disk.
^{After the 100} Mo powder or pellets are formed on the disk, it is optional to solidify the ¹⁰⁰ Mo material by a process such as arc melting or electron beam melting.
Sintering is performed at about 1200 ° C. to about 2000 ° C., about 1500 ° C. to about 2000 ° C., about 1300 ° C. to about 1900 ° C., about 1400 ° C. to about 1 ° C. under an oxygen-free atmosphere provided by an inert gas (eg, argon). 1800 ° C, should be performed at a temperature in the range of about 1400 ° C to about 1700 ° C, in an inert atmosphere for a period in the range of 2-7 hours, 2-6 hours, 4-5 hours, 2-10 hours is there.

Alternatively, the sintering process may be performed under vacuum. Suitable dimensions for a ¹⁰⁰ Mo target disk are about 8 mm to about 20 mm, about 10 mm to about 18 mm, about 12 mm to about 15 mm, and a suitable density for a ¹⁰⁰ Mo target disk is about 4.0 g / cm ³ to about 12.5 g / cm ³ , about 6.0 g / cm ³ to about 10.0 g / cm ³ , about 8.2 g / cm ³ .
2 for engaging the end 81 of the target holder 80 with the cooling pipe holder 105 of the cooling water supply pipe 103 or the cooling water supply pipe 154 (see FIGS. 18A and 18B). One or more grooves 82 are provided.

FIG. 9 shows a vertical cross-sectional view of an exemplary target holder 80. Here, the target holder 80 comprises 18 ¹⁰⁰ Mo target disks that are securely engaged in the target radiation chamber 42 such that the flux of bremsstrahlung photons generated by the bremsstrahlung transducer station 70 is illuminated. Is housed.
13 and 14 are a side view and a top view of the target holder 80 fixed at a predetermined position by the cooling pipe holder portion 105 (see FIGS. 16A to 16C) of the cooling water supply pipe 100. FIG. It is each enlarged view of. Here, the target holder 80 is arranged so as to be irradiated with a flux of bremsstrahlung photons.

FIGS. 17 and 18 illustrate another exemplary embodiment cooling water supply tube assembly 153 disposed within the refrigerant tube housing 144.
The cooling water supply pipe assembly 153 generally includes a cooling water pipe 154. The cooling water pipe 154 includes a plurality of cooling pipe guide fins 155 around the distal end, a cooling pipe holder 156 (see FIG. 17A) at the distal end, and a holding ring 162 at the generally proximal end. (See FIG. 17B).
The cooling water supply pipe 154 includes an outer shield 157, an inner upper shield 158 (see FIG. 17B), and an inner lower shield (not shown).
A refrigerant tube cap assembly 141 including a refrigerant tube cap body 142 that is integrally engaged with the upper end portion of the refrigerant tube housing 144 is provided at the upper end portion of the refrigerant tube housing 144 (see FIGS. 17 and 18).
The refrigerant pipe cap body 142 has an integral shoulder 143 for seating the refrigerant pipe holding ring 162 (see FIGS. 18A and 18B).

The refrigerant pipe cap assembly 141 also includes a flange 147 that is interposed between the refrigerant pipe cap body 142 and a collar 145 that is integrally engaged with the upper portion of the refrigerant pipe cap body 142. .
The refrigerant tube cap collar 145 has a plurality of vertical channels 146 around the inner diameter, and each vertical channel 146 has a continuous horizontal channel 146a (see FIG. 17A).
Further, after the cooling water supply pipe assembly 153 is mounted in the refrigerant pipe housing 144, a refrigerant pipe cap 151 is provided that engages with the refrigerant pipe cap collar 145 so as to be sealed (FIG. 18A). 18 (B)).

The refrigerant pipe cap 151 has a plurality of outward projecting portions 151a. The plurality of outward projecting portions 151a are spaced around the side wall of the refrigerant tube cap 151 so as to be slidably engaged with the plurality of vertical channels 146 and the horizontal channel 146a of the refrigerant tube cap collar 145. Has been placed.
A refrigerant tube cap lifting loop 152 is attached to the upper portion of the refrigerant tube cap 151. Thereby, the refrigerant pipe cap 151 is separably engaged with the refrigerant pipe cap collar 145 by the crane hook 266 operated by a remote control operation of the molybdenum processing apparatus (see FIGS. 18A, 19 and 23). .

Another exemplary embodiment of the present disclosure relates to a remotely controlled molybdenum processing apparatus.
Remote control molybdenum processing equipment transports the target holder along with multiple ¹⁰⁰ Mo target disks to the target assembly station for irradiating high flux high energy bremsstrahlung photons and recovers the target holder irradiated from the target assembly station Then, the irradiated target holder is moved to the lead shield cask and sealed, and then the lead shield cask is moved to a transfer device for moving from the linac irradiation facility.
The remote control molybdenum processor 200 is also used to insert and retrieve the cooling water supply tube assembly from the target assembly station.

A suitable exemplary remote control molybdenum processing apparatus 200 is shown in FIGS. The remote control molybdenum processing apparatus 200 also generally includes a frame structure 230 with an X direction carriage assembly 240 attached for remote control transport of the Z direction carriage assembly 250 in a horizontal plane.
The Z-direction carriage assembly 250 moves the grapple assembly 256 (see FIGS. 24A and 24B) in the vertical plane.
The remote control molybdenum processing apparatus 200 is mounted on a frame support 202 (see FIG. 20). The frame support 202 is secured to a protective shield sheath 15 (see FIG. 19) that surrounds the target assembly station portion 30 of the exemplary system 10 shown in FIG.

Frame structure 230 of the remote control molybdenum processor 200 is fixed to the frame support table 202 (see FIG. 20), also for example, in the form of inverted tee rail 203 which is processed by the stainless steel, the two major support Part. The tee rail 203 has a mounting hole pattern that matches a bolt hole (not shown) of the target chamber shield.
The tee rail 203 extends in parallel with the linac, is placed on the upper part of the protective shield outer member 15, and is a steel block (not shown) existing under the protective shield outer member 15 surrounding the target assembly station 30. Are fastened with screws.
Several crossbars 204 hang on the two support tee rails 203 to provide structural support.
The end of the frame support 202 closest to the linac has an assembled structure channel 206 that supports one end of the frame structure 230 and the fixed end of the shuttle tray pneumatic cylinder 209.

A mounting plate 208 for the other end of the frame structure 230 is disposed away along the support tee rail 203.
Shuttle guide rail 210 is bolted to a backing plate (not shown) bolted across support tee rail 203.
The shuttle guide rail 210 supports the vertical movement of the shuttle tray 212 perpendicular to the main support tee rail 203 in the vertical direction and guides it in the horizontal direction.
A long drip tray 220 is supported on several cross bars 204. This drip tray 220 serves to collect and prevent leaking so that any contaminated cooling water that drips from the cooling tube assembly or flows through the chamber lid is treated (as described below).

The drip tray 220 is assembled in two pieces to allow assembly around a port 222 that provides access to the cooling tower station 32 of the target assembly 30 (see FIGS. 4 and 5).
Joints and openings around the port 222 are dam-shaped and sealed to minimize leakage. Each end of the drip tray 220 is provided with a bottom drain point connected to a capped elbow (not shown).
Drain hoses can be temporarily attached to these elbows to collect effluent from the decontamination solution.
The drip tray 220 includes four pins that serve as removable attachment points 219 for the tilt tower assembly (270 in FIG. 25) and a tilt tower rest 221. As used herein, the term “removable” means that a component (eg, tilt tower assembly) can be temporarily secured to an attachment point and then removed and transferred.

The shuttle tray 212 is formed by welding, for example, into a stainless steel pan shape having a length of about 700 mm, a width of about 250 mm, and a depth of about 30 mm (see FIG. 21).
The shuttle tray 212 includes a plurality of track rollers (not shown) (a) attached to four studs for vertical support during operation, and 2 for holding a horizontal arrangement during operation. Two track rollers (not shown) (b) are provided.
The shuttle tray 212 has a shield cask base 292 on the plurality of vertical alignment pins 214, a shield cask lid 295 (see FIG. 21) in the receptacle 216, and a refrigerant pipe cap 151 (see FIG. 18A) in the receptacle 218. , 18 (B)) are transported laterally so that they are positioned in a position directly below the remote controlled molybdenum processing apparatus 200 for reliable positioning and further remote control.

The shield cask 290 is manually attached (and removed) to the shuttle tray 212 prior to the start of the remote processing operation and after the remote processing operation is completed.
The two vertical alignment pins 214 are used to align and stabilize the shield cask base 292 on the shuttle tray 212.
Using the crane hook 266 engaged by the grapple assembly 256 (see FIGS. 23, 24) by the remote control molybdenum processor 200, both the shield cask lid 295 and the refrigerant tube cap 151 are remotely removed and , Each mounted on a shield cask base 292 or refrigerant tube housing 144.
In order to ensure a continuous collection path for possible dripping of contaminated water that may occur during collection and attachment of the cooling tube assembly 153 after irradiation of the target holder 80 packed with the target disk 85, the shuttle tray 212. Slightly covers one end of the drip pan 208.

The shuttle tray 212 is also provided with a bottom drain port 213 and a capped elbow for discharging the decontamination liquid in the future.
The shuttle tray 212 is moved by two 10.0: 1.5 high stroke / bore duty ratio pneumatic cylinders 209 bolted together in a back-to-back arrangement.
Bolting these two cylinders back to back to achieve the three positions movably allows two unique cylinder configurations to obtain a central position.
Movement to the refrigerant pipe receptacle 218 position is realized by extending both cylinders. Movement to the position of the shield cask lid receptacle 216 is realized by extension of one of the cylinders. The movement to the position of the shield cask base 292 is realized by retracting both cylinders.

The remote control molybdenum processing apparatus 200 is a main remote processing mechanism for transporting the target holder 80. Here, the target holder 80 is provided with a plurality of ¹⁰⁰ Mo target disks, and is inserted into the cooling tower 32 of the target assembly 30 and then remote-processed with respect to the holder 80 to be processed in the horizontal direction (X) and the vertical direction ( After supplying all the working beam paths to Z), it is removed.
Remote control Molybdenum processor 200 comprises a grapple assembly 256, grapple assembly 256, pneumatic clamps chip 264, downward looking camera 225 and an overhead remote control molybdenum processing apparatus 200, and around the working area A pair of light emitting diode (LED) spotlights (not shown) is provided.

The exemplary frame structure 230 of the present invention is a four-leg structure bolted to the frame support 202. The frame structure 230 can be made from a plurality of extruded aluminum structure frames.
The frame structure 230 has two main girders 232 that extend parallel to the linac. These girders 232 are brazed together at each end of the frame structure 230 to maintain precise spacing and provide structural rigidity.
These girders and braces provide support for the X-direction drive motor and gearbox, cable carrier, electrical conduit, and junction box.
In the exemplary embodiment shown in FIGS. 19 and 23, the two main girders 232 that directly support the two X-direction linear actuators are spaced about 440 mm apart.

The X direction carriage 240 is attached between two X direction linear actuators 242. X-direction carriage 240, the motor in the Z-direction carriage 250, gearbox, and the linear actuator, and supports the LED spotlight and downward camera 225.
Two vertical Z-direction drive actuators 252 are mounted between two X-direction drive actuators 242, and two Z-directions for performing remote processing operations on the tilt tower assembly 270 (see FIG. 25). In order to provide an appropriate distance between the drive actuators 252, they are spaced about 270 mm apart. Z-direction carriage 250 supports the grapple assembly 25 6.

The linear actuator in both the X direction drive and the Z direction drive is preferably a rail guide type on the inner side surface (profile) of the ball screw drive.
Each unit is composed of a square extruded aluminum body. This extruded aluminum body has an internal circulating ball carriage with an integral ball nut riding on an inner rail driven by a 5 mm pitch rotating ball screw.
In order to protect internal driving components from water splashes and dust, an external load carriage is attached to the internal guide carriage via a stainless steel cover band.
Actuators and gearboxes are manufactured in a lubricated state with unique radiation-resistant polyphenol polyether grease.
Both X and Z direction actuation is performed (powered) by both of these linear actuators, and the X and Z direction carriages are assembled so as not to interfere with this actuation.

Each of the X and Z direction drive motors is a radiation-resistant stepping motor including a fail-safe brake (which is separated from power by applying a spring) and a brushless resolver.
Resolvers are provided in this environment because optical encoders are prone to browning and premature failure in high radiation fields.
The output drive shaft of each motor is connected to a tamper-evident prevention torque-limited safety coupling to prevent mechanical overload of the drive unit.
The X direction torque limiter is tripped with a torque of 1.13 Nm (10 in-lbs) and the Z direction drive torque limiter is tripped with a torque of 2.26 Nm (20 in-lbs).
When tripped (released), these torque limiters attempt to automatically re-engage with the shaft rotation of all motors. Once the overload is removed and the speed is reduced, the torque limiter is re-engaged.
These torque limiters are bi-directional and are estimated to exceed the maximum load mass of the manipulator, so even if the torque limiter is released during lifting, It is not allowed to descend in a manner that is not done.

Since these torque limiters are not friction type limiters, no adjustment is required from start to finish. The motor speed can be adjusted indefinitely by joystick control from zero to a maximum set speed of about 300 revolutions per minute (rpm).
A ball screw pitch of about 5 mm and a gear ratio of about 1: 1 provides a maximum linear actuator speed of about 25 mm / sec.
In both the X and Z direction drives, the safety overload coupling is attached to the input shaft of the dual output shaft gearbox. A right angle gearbox is connected to each end of the dual output gearbox.
Output shafts of the right angle gearbox through a mosquito Ppuringu, is connected to an input shaft of the linear actuator.

Since the dual output gearbox is a solid shaft, one output shaft rotates clockwise with respect to the mounting surface, and the other output shaft rotates counterclockwise.
As a result, the pair of linear actuators consists of a right-handed ball screw and a left-handed ball screw. The ball screw of each set of linear actuators is adjusted to a pitch over the travel length of the ball screw of about 0.04 mm, which is smaller than the play of the shaft end bearing.
This alignment prevents the two drive screws from sticking to each other when touching through a carriage that is firmly assembled in the X or Z direction.

The entire movement range of the linear actuator is about 1850 mm in the X direction and about 1250 mm in the Z direction. However, a plurality of proximity detectors are arranged near the moving ends to prevent the internal actuator carriage from moving to the moving ends.
Therefore, the actual movement range is about 1800 mm in the X direction and about 1200 mm in the Z direction, respectively.
19 and 23, the close position of the proximity detector in the X direction and the high position of the proximity detector in the Z direction are the home of the remote control molybdenum processing apparatus 200 for zeroing the resolver readout again. Set as position .
Remote processing operation of all, accurate positioning of the remote control operating device, located, and to ensure engagement, for example by overhead and therewith perpendicular, minimum of two closed-circuit television camera according to the camera view Be monitored.

Spotlights (eg, a pair of LED spotlights) may be provided to enhance the operator's skill to perceive depth through the use of shadows.
To make this possible, each light is controlled individually. The camera is a pan, tilt, and network enabled color camera equipped with zoom function.

The grapple assembly 256 (see FIG. 24) is a small, custom designed lifting device that engages and lifts the pneumatic clamp tip 264 of the grapple assembly 256 with either the target holder 80 or the crane hook 266 and the loading part.
Engagement with either of these two parts is such that the pneumatic clamp tip 264 of the grapple assembly first operates horizontally to center the part and then vertically to contact and lift the part. This is done by operating on.
To allow centering in the horizontal direction, the grapple skeleton 258 is fork with two tapered protrusions leading to a semi-circular opening ring.
The two protrusions and ring have a lip at the lower edge. This lip engages the bottom surface of the flat surface provided on both the parts to be lifted .

Because this exemplary embodiment does not have any vertical characteristics on the lip of the grapple skeleton 258 that resist horizontal sliding of the parts being lifted, the grapple assembly 256 has a spring retract pneumatic clamp cylinder. 260 is provided. This cylinder 260 inserts the tip of the plunger into the matching recess at the top of both parts to be lifted.
The plunger tip enters this recess and applies a force of about 175 N (40 lbf) from the cylinder 260 to prevent the lifted part from sliding off the grapple assembly 256 during operation.
When the lock plunger is engaged, the part being lifted is effectively secured to the grapple assembly 256. However, to release the parts attached to the grapple assembly 256, the spring retract plunger is automatically retracted by stopping the air supply to the cylinder 260.

Inadvertent air loss also causes the plunger to retract, but this does not correspond to the part being dropped.
Even if sufficient horizontal force is generated by impact or sudden deceleration, the part being lifted simply means that it has slid forward from the grapple assembly 256.
Also, when operating the hook adapter 266, the clamp cylinder 260 provides some degree of mechanical compliance in the horizontal direction. The conical shape surrounding the flat engagement on the hook adapter 266 allows the hook adapter 266 to swing back and forth relative to the grapple assembly 256.
When following the arc trajectory required for the operation of the tilt tower, a slight swing is required. This plunger allows this oscillating operation without releasing the hook adapter 266.

To assist the horizontal operation, grapple assembly 256 can comprise a ball conveying unit 257 of the three smaller on the bottom of the grapple assembly body.
These ball transporting unit 257, when it is moved in the horizontal direction, grapple assembly 256 to be moved by rolling along one surface.
Ideally, the ball conveying unit 257, a suitable fit surface of the parts to be acquired, until lightly physical contact, grapple assembly 256 drops.
Thereafter, the ball conveying unit 257 functions as a positive direction of the lower stop. However, some vertical mechanical compliance is built into the grapple assembly 256 because the manipulator does not provide any force feedback and all operations are under remote control.

Attached to the bottom of the Z-direction carriage 250, the upper body of the grapple assembly 256 is bolted to the lower body of the grapple framework 258 via a spring biased sliding sleeves 254 (spring 259).
This arrangement of the sliding sleeve allows an overtravel of about 10 mm vertically downward without overloading the Z-direction drive and accidentally releasing the safety torque limiter.
This also limits the force applied to the ball conveying unit 257, to allow for smooth horizontal rolling motion. The spring 259 of the sliding sleeves 254, to allow only overtravel downward, does not form part of the path of loading lifted components.

Another exemplary embodiment of the present disclosure relates to a tilt tower that is part of a remote processing device and that is also part of a remotely processed device.
A suitable exemplary tilt tower assembly 270 is shown in FIGS. The tilt tower assembly 270 generally includes a tower weld, a pivot guide base with a lever arm assembly, and a tower rest assembly.

The tilt tower assembly 270 is used to support a cooling tube assembly 153 that carries the target holder 80. On the other hand, the cooling tube assembly 153 rotates with the grapple assembly 256 in the remote control molybdenum processing apparatus 200 and is lowered from the vertical position to the horizontal position to the horizontal position as necessary. To be combined.
The target holder 80 is (i) inserted into and removed from the shield cask 290 in the vertical direction, and (ii) after the tilt tower assembly 270 is lowered about the axis in a horizontal position, It is necessary for the target holder 80 to rotate in order to align horizontally for insertion into and removal from the cooling tube assembly 153 engaged with the tilt tower assembly 270.

The tilt tower assembly 270 includes a tilt tower weld that is pivotally engaged with a pivot guide base.
A suitable exemplary tilt tower weld (best seen in FIG. 25) includes a pair of elongated bars 274 spaced by an upper support plate 272 and a lower support plate 273.
The support plates 272 and 273 are structurally reinforced at predetermined positions by a plurality of support braces 275.
The upper support plate 272 and the lower support plate 273 are provided with matching tapered grooves with arcuate ends for receiving and placing the cooling tube assembly 153 therein.
The cooling pipe assembly 153 is supported on the upper support plate 272 by placing the refrigerant pipe holding ring 162 of the cooling pipe assembly 153 on the upper support plate 272.

The lower support plate 273 provides a second support point for the cooling tube assembly 153 that is required when the cooling tube assembly 153 is in a horizontal orientation.
The tilt tower weld has three round bars that pass between two major support angles. An upper round bar 276 (also referred to as an upper round shaft) is engageable with a crane hook 266 that cooperates with the grapple assembly 256 to raise and lower the tilt tower assembly 270.
The upper round bar 276 includes two tapered disks disposed generally at the center of the bar 276 for guiding the crane hook 266 in place.
A bottom round bar 284 (also referred to as a bottom round shaft) provides a pivot point for lowering the tilt tower assembly 270 in one horizontal position.

An intermediate round bar 279 (also referred to as an intermediate shaft) functions as a stop when the tilt tower assembly 270 is raised to a predetermined vertical position, and a lever when the tilt tower assembly 270 is lowered to one horizontal position. It functions as an operating mechanism for the arm 286 (see FIG. 26).
Both ends of the bottom round bar 284 and the intermediate round bar 279 extend through the side surfaces of the two elongated rectangular bars 274.

The tilt tower assembly 270 includes a pivot guide base. The pivot guide base cooperates with the tilt tower weld to lower the tilt tower assembly 270 about the axis in one horizontal position and raise the tilt tower assembly 270 about the axis to one vertical position.
The pivot guide base has a bottom plate 280 secured to a pair of spaced apart matching side plates 282.

  The pair of side plates 282 are parallel to and adjacent to (i) an inclined upper edge portion that recedes downward from the first side end portion to the opposite side end portion, and (ii) the “longer” side end portion of the side plate 282. At the selected first position above the bottom plate 280, and (iii) the adapted vertical guide groove parallel to and adjacent to the “shorter” side end of the side plate 282; A selection of the lower crossbar 287 to be fitted, and (v) an upper selection of the lower crossbar 287, which is secured across a matching vertical guide groove adjacent to the “longer” side edge of the two side plates 282 And a conforming upper cross bar 288 secured across the conforming vertical guide groove adjacent to the “longer” side end of the two side plates 282.

Further, both ends of the bottom round bar 284 extending outward from the two elongated square bars 274 are “long” of the two side plates 282 between the two lower cross bars 287 and the two upper cross bars 288. Extends outwardly through an adapted vertical guide groove adjacent to the “side” end.
Further, both ends of the intermediate round bar 279 extending through the side surfaces of the two elongated rectangular bars 274 are adjacent to the “longer” side end of the two side plates 282 above the two upper cross bars 288. And extends outward through the adapted vertical guide groove.
The lever arm assembly 286 is rotatably attached to the bottom plate 280.

The guide groove of the side plate 282 captures, guides, and arranges both ends of the bottom round bar 284 and the middle round bar 279 that extend outward through the sides of the two elongated square bars 274.
In the vertical direction, both ends of the bottom round bar 284 are captured in the “longer” vertical guide groove between the two lower crossbars 287 and the two upper crossbars 288. Meanwhile, both ends of the intermediate round bar 279 are captured in the “longer” vertical guide groove above the upper crossbar 288, thereby holding the tilt tower assembly 270 upright.
In operation where the cooling tube assembly 153 is attached to the tilt tower assembly 270, the pivot guide base bottom plate 280 is fitted over the four pins of the drip tray 220 that serve as the attachment point 219 (see FIG. 20) for the tilt tower 270. .

When it is desirable to move the tilt tower assembly 270 from one vertical position to one horizontal position, or vice versa, the upper round bar 276 is attached to the grapple assembly 256 of the remote control molybdenum processor 200 by a crane hook 266. Engage with. The tilt tower assembly 270 can then be lifted until both ends that extend outside the bottom round bar 284 abut the upper crossbar 288.
At this position, both end portions of the intermediate round bar 279 that extend outwardly protrude from the “longer” vertical guide groove of the side plate 282.

As a result of the remote control of the molybdenum treatment apparatus 200, the tilt tower assembly 270 is pivoted from a predetermined vertical upright position to a horizontal position in a horizontal plane parallel to the frame support 202 by remote control operation of the grapple assembly 256. Lowered around. At the same time, both end portions of the intermediate round bar 279 that extend to the outside slide along the inclined upper edge portion that recedes downward from the first side end portion of the side plate 282 to the opposite side end portion. Lower the top of the tilt tower assembly 270 about the axis.
When both ends extending outward of the intermediate round bar 279 reach the end of the inclined upper edge of the side plate 282, the sliding of the intermediate round bar 279 causes the “shorter” vertical guide groove of the side plate 282 to slide. Stopped by engagement.

In the fully lowered position, the tilt tower assembly 270 is supported by engagement of the upper support plate 272 and the tilt tower rest 221 provided on the drip tray 220 (see FIGS. 20 and 26).
When the upper portion of the tilt tower assembly 270 is lowered about the axis, a part of the intermediate round bar 279 interposed between the two elongated rectangular bars 274 is pressed against one end of the lever arm 286 and the other end of the lever arm 286 is Raise the department.
The rising end of the lever arm 286 has a round extension tip (not shown). This extended tip contacts the target holder 80 engaged with the refrigerant tube assembly 153, lifts the target holder 80 several millimeters, and the pneumatic clamp tip 264 of the grapple assembly 256 properly engages the target holder 80, Allows removal from the refrigerant tube assembly 153.

  The operation of the high power linac electron beam device 10 of the present disclosure generally includes the following steps.

The first step is to prepare a molybdenum 100 target disk for loading into the target holder 80.
The molybdenum disk can be prepared from naturally occurring molybdenum powder (9.6% Mo-100 isotope abundance) or highly concentrated Mo-100 powder.
This highly concentrated Mo-100 powder is finely pulverized or otherwise adjusted before being placed in a disk mold.
This mold is placed in a hydraulic press and the disc is pressed. The pressed disc is nominally about 15 mm in diameter and about 1 mm thick.
Subsequent high temperature sintering in a reducing or inert atmosphere furnace reduces the disk by about 4% in diameter and about 3% in thickness.

After pressing and sintering, the individual target disks are manually loaded into the target holder 80, and the loaded target holder 80 is manually loaded into the lead-lined shield cask 290.
Processing the preparatory Mo-100, pressing onto the disk before sintering, and then loading the sintered disk into the target holder 80 is preferably limited so that the molybdenum powder does not leave the working environment. To be done in the glove box.
After removal from the glove box, the shield cask 290 loaded with the target holder 80 is lifted by the crane hook 266 engaged with the handle 296 (see FIG. 22) of the shield cask lid 295. Thereafter, the shield cask 290 is placed on the shuttle tray 212 by lowering the shield cask base 292 onto the plurality of pins 214 provided on the shuttle tray 212 by an overhead crane (not shown) ( 19 and 21).

After the shield cask lid 295 is opened from the shield cask base 292 by unlocking the plurality of handles 294, the shield cask lid 295 is moved onto the shuttle tray 212 by the crane and is provided in the shuttle tray 212. Placed on the received receptacle 216.
Thereafter, the refrigerant pipe cap 151 is removed from the refrigerant pipe cap assembly 141 by the grapple assembly 156 of the remote-control molybdenum processing apparatus 200 (see FIGS. 18A and 18B) and provided in the shuttle tray 212. Placed on the receptacle 218. Here, the refrigerant pipe cap assembly 141 extends upward from the refrigerant pipe housing 144 communicating with the target irradiation chamber 42 (see FIG. 9).
The upper portion of the cooling tube assembly 153 engages the grapple assembly 256 and is lifted from the refrigerant tube housing assembly 144 and the refrigerant tube retaining ring 162 is disposed on the upper support plate 272 of the inclined column assembly 270 to thereby tilt the tower. Mounted on assembly 270.

Thereafter, the inclined tower weld is moved from the predetermined vertical position to the horizontal position described above by remote control of the grapple assembly 256.
The grapple assembly 256 is then remotely operated to engage the plurality of grooves 82 at one end of the target holder 80 with the pneumatic clamp tip 264 of the grapple assembly 256. Thereafter, by remote control of the grapple assembly 256, the target holder 80 is removed from the shield cask base 292, and is inserted into the cooling tube holder 156 at the bottom end of the cooling water supply tube 154 and fixed.
Thereafter, the tilt tower weld is moved from a predetermined horizontal position to a vertical position by remote control of the grapple assembly 256.

The grapple assembly 256 is then used to remove the cooling tube assembly 153 to which the target holder 80 is attached from the tilt tower assembly 270 and then the cooling tube assembly 153 is moved until the target holder 80 enters the target irradiation chamber 42. Lower into cooling tube housing 144.
Thereafter, the target holder 80 can be accurately controlled by remotely controlling the refrigerant supply tube 103 (or refrigerant tube assembly 153) so that the photon flux generated by the bremsstrahlung transducer station 70 is maximized. Placed and aligned.
Thereafter, the upper hub assembly of the cooling water supply pipe 141 is sealed in the refrigerant pipe housing 144 by attaching the refrigerant pipe cap 151.

Thereafter, a first cooling water pressure supply system is attached to the cooling water supply pipe 50 so as to circulate the cooling water alone via the bremsstrahlung transducer station 70.
Thereafter, the second cooling water pressurization supply system seals the water inlet pipe 46 so as to circulate the cooling water through the target holder 80, the ¹⁰⁰ Mo target disk 85, and the radiation chamber 55 of the target irradiation chamber 42. To be attached.
Thereafter, the linac 20 is activated to produce an electron beam for irradiating the tantalum plate 26 housed in the bremsstrahlung transducer station 70. Here, the bremsstrahlung transducer station 70 generates a bremsstrahlung photon shower to illuminate a target holder 80 loaded with a plurality of ¹⁰⁰ Mo target disks 85.

When irradiating the target holder 80 containing a plurality of ¹⁰⁰ Mo target disks 85 using the high-power linac electron beam apparatus 10 having the 35 MeV, 40 kW electronic linac 20 disclosed in the present specification, it takes about 24 hours. About 96 hours, about 36 hours to about 72 hours, about 24 hours, about 36 hours, about 48 hours, about 60 hours, about 72 hours, about 80 hours, about 96 hours, the target holder 80 and the disc 85 are Irradiation is desirable.
After providing irradiation to the ¹⁰⁰ Mo target disk 85 for a selected period, the linac 20 is turned off, the two cooling water supplies are stopped, and the cooling water in the target irradiation chamber 42 is drained.
After the cooling water supply from the water inlet pipe 46 is stopped, the refrigerant pipe cap 151 is separated from the refrigerant pipe cap assembly 141 by the remote control of the grapple assembly 256 of the molybdenum processing apparatus 200 and provided in the shuttle tray 212. Located on the receptacle 218.

Thereafter, the cooling tube assembly 153 is operated by remote control of the grapple assembly 256 to securely engage the irradiated target holder 80. Thereafter, the cooling tube assembly 153 is removed from the refrigerant tube housing 144 and the refrigerant tube retaining ring 162 is placed on the upper support plate 272 of the inclined tower assembly 270 so that the cooling pipe assembly 153 is moved into the inclined tower assembly 270. Placed in.
Thereafter, the inclined tower weld is moved from the predetermined vertical position to the horizontal position described above by remote control of the grapple assembly 256.
The grapple assembly 256 is then remotely operated to engage the plurality of grooves 82 at one end of the target holder 80 with the pneumatic clamp tip 264 of the grapple assembly 256. Thereafter, by remote control of the grapple assembly 256, the irradiated target holder 80 is removed from the cooling tube assembly 153 and inserted into the shield cask base 292.

Thereafter, the shield cask lid 295 is placed on the shield cask base 292 by the grapple assembly 256 and fixed in place by engaging a plurality of shield cask handles 294 with the shield cask lid 295.
The shield cask 290 can then be moved into the glove box by an overhead crane to transfer the irradiated target holder 80.

Here, it is optional to transport the target holder 80 loaded with the irradiated ¹⁰⁰ Mo target disk 85 housed in a lead-lined transport container to a ^99m Tc recovery facility.
Alternatively, the target holder 80 loaded with the irradiated ¹⁰⁰ Mo target disk 85 can be transported into the hot cell by remote control and ^99m Tc can be obtained using equipment and methods known to those skilled in the art. , Separated from the irradiated ¹⁰⁰ Mo target disk 85 and recovered.
An example of a suitable instrument for separating and recovering ^99m Tc is the TECHNEGEN® isotope separation device (TECHNEGEN is a registered trademark of North Star Medical Radioisotope LLC, Madison, Wisconsin, USA). The
^{After 99m} Tc recovery is complete, ¹⁰⁰ Mo is recovered, dried, and modified to a disk for sintering using methods known to those skilled in the art.

The exemplary high power linac electron beam device disclosed herein generates a 40 kW, 35 MeV electron beam, and the generated electron beam is a bremsstrahlung photon shower for irradiating a plurality of ¹⁰⁰ Mo target disks. Is converted to ⁹⁹ Mo is produced through the photonuclear reaction of a ¹⁰⁰ Mo target.
This high-power linac electron beam device is made from about ¹⁰⁰ Curie (Ci) to about 50 Curie (Ci) from multiple irradiated ¹⁰⁰ Mo target disks with an overall weight of about 12g to about 20g, about 14g to about 18g, about 15g to about 17g It has the ability to routinely produce 220 Mo, about 60 Ci to about 160 Ci, about 70 Ci to about 125 Ci, about 80 Ci to about 100 Ci in ⁹⁹ hours.
Allocating 48 hours to ⁹⁹ Mo decay from multiple irradiated ¹⁰⁰ Mo target disks, about 35 Ci to about 65 Ci, about 40 Ci to about 60 Ci, about 45 Ci to about 55 Ci in one day for shipment to nuclear pharmacy Will result in the production of ⁹⁹ Mo.

The exemplary high power linac electron beam device disclosed herein relates to a 40 kW, 35 MeV electronic linac for producing ⁹⁹ Mo from a plurality of irradiated ¹⁰⁰ Mo target disks, It can be scaled up to about 100 kW electron beam power or scaled down to about 5 kW electron beam power.

Claims (15)

An apparatus for producing molybdenum-99 ( ⁹⁹ Mo) from a ¹⁰⁰ Mo target via a photonuclear reaction of a plurality of molybdenum-100 ( ¹⁰⁰ Mo) targets, the apparatus comprising:
It is possible to generate electron beams, and a linear accelerator,
In response to the electron beam, it is possible to generate Braking radiation photon shower, a transducer unit,
A target irradiator having a chamber for receiving and detachably engaging a target holder containing a plurality of ¹⁰⁰ Mo target disks and receiving a bremsstrahlung photon shower ;
Said device the can be conveyed in the apparatus along a, it is possible to Disconnect engage preparative and one end of the target holder, and a remote control grapple assembly,
It engaged to seal with the transducer unit, for circulating a coolant fluid, the cooling system,
Apparatus comprising: a. The linear accelerator system of claim 1, wherein the benzalkonium which having a power of at least 10kW to about 100 kW.   The apparatus of claim 1, wherein the transducer section comprises at least one metal plate arranged to block an electron beam generated by the linear accelerator. The metal plate is copper, cobalt, iron, nickel, palladium, rhodium, silver, tantalum, tungsten, zinc or any of those metals alloys, according to claim 3, characterized in that it comprises a plate apparatus. Removably engage with the target holder; ¹⁰⁰ The apparatus of claim 1, comprising a cooling tube assembly configured to circulate a second refrigerant through the Mo target disk. 6. The apparatus of claim 5, wherein the cooling pipe assembly comprises a refrigerant supply pipe having a plurality of guide fins and a cooling pipe shield for shielding a bremsstrahlung photon shower. The apparatus according to claim 1, wherein the target irradiation unit includes a target alignment unit for arranging and aligning the target holder so as to block the bremsstrahlung photon shower as much as possible. The apparatus of claim 1, wherein the bremsstrahlung photon shower has an energy of at least 20 MeV to about 45 Mev. By remote control, the target holder and dispensing apparatus of claim 1, the photon flux and further comprising a device for transporting the container feed transportable to ¹⁰⁰ Mo target disk irradiated. Accepting the target holder containing the ¹⁰⁰ Mo target disk irradiated with photon flux, and separating and recovering technetium- ^99m ( ^99m Tc) from the ¹⁰⁰ Mo target disk irradiated with this photon flux, The apparatus of claim 1, further comprising a hot cell for processing the ¹⁰⁰ Mo target disk. The apparatus according to claim 1, further comprising a removable protective sheathing that surrounds the linear accelerator and the target irradiation unit. The apparatus of claim 1, comprising a frame structure attachable to an upper portion of the apparatus, wherein the remote control grapple assembly can be transported within the frame structure along the frame structure. Multiple molybdenum-100 ( ¹⁰⁰ Mo) through the photonuclear reaction of the target, ¹⁰⁰ Mo-molybdenum-99 ( ⁹⁹ Mo) for producing a process comprising the steps of:
Generating an electron beam using a linear accelerator;
Generating a bremsstrahlung photon shower from an electron beam;
A plurality of contained in a target holder for receiving a bremsstrahlung photon shower ¹⁰⁰ Illuminating the Mo target disk;
Irradiated ¹⁰⁰ Cooling the Mo target disk by circulating refrigerant fluid;
Photon flux was irradiated using a remote control grapple assembly that could be removably engaged with one end of the target holder. ¹⁰⁰ Technetium-99m from Mo target disk ( ^99m Transporting said target holder for separating and recovering Tc). The method of claim 13, wherein the bremsstrahlung photon shower has an energy of at least 20 MeV to about 45 MeV. The method of claim 14, wherein the linear accelerator has a power of at least 10 kW to about 100 kW.